Failed to scan files: Cloud error 403: HTTP/1.1 403 Forbidden - The request signature we calculated does not match the signature you provided
If you get this error backing up (etc) to the Cloud using Amazon S3 (not to be confused with Amazon Drive), it may be because you are using a custom URL that includes the bucket name. Try setting this back to [default]. (Note that some preliminary operations such as listing buckets may work fine with the custom URL in place, but it generally results in a scan error later)
You also receive a 403 Forbidden error when using Amazon Drive. This is because Amazon has stopped all 3rd party access to Amazon Drive, therefore it is no longer supported by SyncBackPro.